CODEWITHSUNDEEP
javascript
Chuck Callebs
Chuck Callebs

Reputation: 16441

Is it possible to ping a server from Javascript?

I'm making a web app that requires that I check to see if remote servers are online or not. When I run it from the command line, my page load goes up to a full 60s (for 8 entries, it will scale linearly with more).

I decided to go the route of pinging on the user's end. This way, I can load the page and just have them wait for the "server is online" data while browsing my content.

If anyone has the answer to the above question, or if they know a solution to keep my page loads fast, I'd definitely appreciate it.

Upvotes: 192

Views: 383249

Answers (18)

sp00ky
sp00ky

Reputation: 161

If you use 'no-cors' the response will not contain any information but will be delayed by latency (tested using clumsy 2.0), but as long as the response contains 'response.status == 0' and 'response.type == opaque', the ping is successful. When I disconnected my internet or tried pinging a non-existant website, 'fetch()' throws an error.

Example js code:

async function pingUrl(url){
  try{
    var result = await fetch(url, {
      method: "GET",
      mode: "no-cors",
      cache: "no-cache",
      referrerPolicy: "no-referrer"
    });
    console.log(`result.type: ${result.type}`);
    console.log(`result.ok: ${result.ok}`);
    return result.ok;
  }
  catch(err){
      console.log(err);
  }
  return 'error';
}

Useful link: https://github.com/whatwg/fetch/issues/1140

Upvotes: 1

Antony Woods
Antony Woods

Reputation: 4462

Pitching in with a websocket solution...

function ping(ip, isUp, isDown) {
  var ws = new WebSocket("ws://" + ip);
  ws.onerror = function(e){
    isUp();
    ws = null;
  };
  setTimeout(function() { 
    if(ws != null) {
      ws.close();
      ws = null;
      isDown();
    }
  },2000);
}

Update: this solution does not work anymore on major browsers, since the onerror callback is executed even if the host is a non-existent IP address.

Upvotes: 8

王玉略
王玉略

Reputation: 3322

const ping = (url, timeout = 6000) => {
  return new Promise((resolve, reject) => {
    const urlRule = new RegExp('(https?|ftp|file)://[-A-Za-z0-9+&@#/%?=~_|!:,.;]+[-A-Za-z0-9+&@#/%=~_|]');
    if (!urlRule.test(url)) reject('invalid url');
    try {
      fetch(url)
        .then(() => resolve(true))
        .catch(() => resolve(false));
      setTimeout(() => {
        resolve(false);
      }, timeout);
    } catch (e) {
      reject(e);
    }
  });
};

use like this:

ping('https://stackoverflow.com/')
  .then(res=>console.log(res))
  .catch(e=>console.log(e))

Upvotes: 4

LifterCoder
LifterCoder

Reputation: 152

let webSite = 'https://google.com/' 
https.get(webSite, function (res) {
    // If you get here, you have a response.
    // If you want, you can check the status code here to verify that it's `200` or some other `2xx`.
    console.log(webSite + ' ' + res.statusCode)
}).on('error', function(e) {
    // Here, an error occurred.  Check `e` for the error.
    console.log(e.code)
});;

if you run this with node it would console log 200 as long as google is not down.

Upvotes: -2

Ohad
Ohad

Reputation: 242

If what you are trying to see is whether the server "exists", you can use the following:

function isValidURL(url) {
    var encodedURL = encodeURIComponent(url);
    var isValid = false;

    $.ajax({
      url: "http://query.yahooapis.com/v1/public/yql?q=select%20*%20from%20html%20where%20url%3D%22" + encodedURL + "%22&format=json",
      type: "get",
      async: false,
      dataType: "json",
      success: function(data) {
        isValid = data.query.results != null;
      },
      error: function(){
        isValid = false;
      }
    });

    return isValid;
}

This will return a true/false indication whether the server exists.

If you want response time, a slight modification will do:

function ping(url) {
    var encodedURL = encodeURIComponent(url);
    var startDate = new Date();
    var endDate = null;
    $.ajax({
      url: "http://query.yahooapis.com/v1/public/yql?q=select%20*%20from%20html%20where%20url%3D%22" + encodedURL + "%22&format=json",
      type: "get",
      async: false,
      dataType: "json",
      success: function(data) {
        if (data.query.results != null) {
            endDate = new Date();
        } else {
            endDate = null;
        }
      },
      error: function(){
        endDate = null;
      }
    });

    if (endDate == null) {
        throw "Not responsive...";
    }

    return endDate.getTime() - startDate.getTime();
}

The usage is then trivial:

var isValid = isValidURL("http://example.com");
alert(isValid ? "Valid URL!!!" : "Damn...");

Or:

var responseInMillis = ping("example.com");
alert(responseInMillis);

Upvotes: 5

Chuck Callebs
Chuck Callebs

Reputation: 16441

I have found someone that accomplishes this with a very clever usage of the native Image object.

From their source, this is the main function (it has dependences on other parts of the source but you get the idea).

function Pinger_ping(ip, callback) {

  if(!this.inUse) {

    this.inUse = true;
    this.callback = callback
    this.ip = ip;

    var _that = this;

    this.img = new Image();

    this.img.onload = function() {_that.good();};
    this.img.onerror = function() {_that.good();};

    this.start = new Date().getTime();
    this.img.src = "http://" + ip;
    this.timer = setTimeout(function() { _that.bad();}, 1500);

  }
}

This works on all types of servers that I've tested (web servers, ftp servers, and game servers). It also works with ports. If anyone encounters a use case that fails, please post in the comments and I will update my answer.

Update: Previous link has been removed. If anyone finds or implements the above, please comment and I'll add it into the answer.

Update 2: @trante was nice enough to provide a jsFiddle.

http://jsfiddle.net/GSSCD/203/

Update 3: @Jonathon created a GitHub repo with the implementation.

https://github.com/jdfreder/pingjs

Update 4: It looks as if this implementation is no longer reliable. People are also reporting that Chrome no longer supports it all, throwing a net::ERR_NAME_NOT_RESOLVED error. If someone can verify an alternate solution I will put that as the accepted answer.

Upvotes: 163

sebilasse
sebilasse

Reputation: 4618

There are many crazy answers here and especially about CORS -

You could do an http HEAD request (like GET but without payload). See https://ochronus.com/http-head-request-good-uses/

It does NOT need a preflight check, the confusion is because of an old version of the specification, see Why does a cross-origin HEAD request need a preflight check?

So you could use the answer above which is using the jQuery library (didn't say it) but with 

type: 'HEAD'

--->

<script>
    function ping(){
       $.ajax({
          url: 'ping.html',
          type: 'HEAD',
          success: function(result){
             alert('reply');
          },     
          error: function(result){
              alert('timeout/error');
          }
       });
    }
</script>

Off course you can also use vanilla js or dojo or whatever ...

Upvotes: 7

garryg
garryg

Reputation: 35

You can run the DOS ping.exe command from javaScript using the folowing:

function ping(ip)
{
    var input = "";
    var WshShell = new ActiveXObject("WScript.Shell");
    var oExec = WshShell.Exec("c:/windows/system32/ping.exe " + ip);

    while (!oExec.StdOut.AtEndOfStream)
    {
            input += oExec.StdOut.ReadLine() + "<br />";
    }
    return input;
}

Is this what was asked for, or am i missing something?

Upvotes: -3

Nils Holgersson
Nils Holgersson

Reputation: 301

Ping is ICMP, but if there is any open TCP port on the remote server it could be achieved like this:

function ping(host, port, pong) {

  var started = new Date().getTime();

  var http = new XMLHttpRequest();

  http.open("GET", "http://" + host + ":" + port, /*async*/true);
  http.onreadystatechange = function() {
    if (http.readyState == 4) {
      var ended = new Date().getTime();

      var milliseconds = ended - started;

      if (pong != null) {
        pong(milliseconds);
      }
    }
  };
  try {
    http.send(null);
  } catch(exception) {
    // this is expected
  }

}

Upvotes: 30

Jerry Wickey
Jerry Wickey

Reputation: 15

just replace

file_get_contents

with

$ip = $_SERVER['xxx.xxx.xxx.xxx'];
exec("ping -n 4 $ip 2>&1", $output, $retval);
if ($retval != 0) { 
  echo "no!"; 
} 
else{ 
  echo "yes!"; 
}

Upvotes: -8

Jerry Wickey
Jerry Wickey

Reputation: 15

It might be a lot easier than all that. If you want your page to load then check on the availability or content of some foreign page to trigger other web page activity, you could do it using only javascript and php like this.

yourpage.php

<?php
if (isset($_GET['urlget'])){
  if ($_GET['urlget']!=''){
    $foreignpage= file_get_contents('http://www.foreignpage.html');
    // you could also use curl for more fancy internet queries or if http wrappers aren't active in your php.ini
    // parse $foreignpage for data that indicates your page should proceed
    echo $foreignpage; // or a portion of it as you parsed
    exit();  // this is very important  otherwise you'll get the contents of your own page returned back to you on each call
  }
}
?>

<html>
  mypage html content
  ...

<script>
var stopmelater= setInterval("getforeignurl('?urlget=doesntmatter')", 2000);

function getforeignurl(url){
  var handle= browserspec();
  handle.open('GET', url, false);
  handle.send();
  var returnedPageContents= handle.responseText;
  // parse page contents for what your looking and trigger javascript events accordingly.
  // use handle.open('GET', url, true) to allow javascript to continue executing. must provide a callback function to accept the page contents with handle.onreadystatechange()
}
function browserspec(){
  if (window.XMLHttpRequest){
    return new XMLHttpRequest();
  }else{
    return new ActiveXObject("Microsoft.XMLHTTP");
  }
}

</script>

That should do it.

The triggered javascript should include clearInterval(stopmelater)

Let me know if that works for you

Jerry

Upvotes: -9

the Tin Man
the Tin Man

Reputation: 160551

The problem with standard pings is they're ICMP, which a lot of places don't let through for security and traffic reasons. That might explain the failure.

Ruby prior to 1.9 had a TCP-based ping.rb, which will run with Ruby 1.9+. All you have to do is copy it from the 1.8.7 installation to somewhere else. I just confirmed that it would run by pinging my home router.

Upvotes: 5

user456733
user456733

Reputation: 351

To keep your requests fast, cache the server side results of the ping and update the ping file or database every couple of minutes(or however accurate you want it to be). You can use cron to run a shell command with your 8 pings and write the output into a file, the webserver will include this file into your view.

Upvotes: 7

Chris
Chris

Reputation: 1697

You could try using PHP in your web page...something like this:

<html><body>
<form method="post" name="pingform" action="<?php echo $_SERVER['PHP_SELF']; ?>">
<h1>Host to ping:</h1>
<input type="text" name="tgt_host" value='<?php echo $_POST['tgt_host']; ?>'><br>
<input type="submit" name="submit" value="Submit" >
</form></body>
</html>
<?php

$tgt_host = $_POST['tgt_host'];
$output = shell_exec('ping -c 10 '. $tgt_host.');

echo "<html><body style=\"background-color:#0080c0\">
<script type=\"text/javascript\" language=\"javascript\">alert(\"Ping Results: " . $output . ".\");</script>
</body></html>";

?>

This is not tested so it may have typos etc...but I am confident it would work. Could be improved too...

Upvotes: -16

jerjer
jerjer

Reputation: 8770

you can try this:

put ping.html on the server with or without any content, on the javascript do same as below:

<script>
    function ping(){
       $.ajax({
          url: 'ping.html',
          success: function(result){
             alert('reply');
          },     
          error: function(result){
              alert('timeout/error');
          }
       });
    }
</script>

Upvotes: 21

wajiw
wajiw

Reputation: 12269

I don't know what version of Ruby you're running, but have you tried implementing ping for ruby instead of javascript? http://raa.ruby-lang.org/project/net-ping/

Upvotes: 0

Eugene
Eugene

Reputation: 11535

You can't directly "ping" in javascript. There may be a few other ways:

  • Ajax
  • Using a java applet with isReachable
  • Writing a serverside script which pings and using AJAX to communicate to your serversidescript
  • You might also be able to ping in flash (actionscript)

Upvotes: 15

esamatti
esamatti

Reputation: 18953

You can't do regular ping in browser Javascript, but you can find out if remote server is alive by for example loading an image from the remote server. If loading fails -> server down.

You can even calculate the loading time by using onload-event. Here's an example how to use onload event.

Upvotes: 8

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